The correlation coefficients between each paired channel of PFC hemodynamic responses were calculated with Pearson’s correlation coefficient that the formula was described in Eq. (1). The male and female groups showed a rather similar distribution of correlation matrices (Fig. 3). The results of correlation matrices represent the strength of resting-state functional connectivity for ΔHbO2, ΔHb and ΔtHb of each paired channel of male and female groups in group-level analysis. In the Fig. 3, the redder boxes represent stronger connection between each PFC region, whereas bluer boxes represent lower connection between each PFC region. Observably, the connection between each pair channel of ΔHbO2, ΔHb and ΔtHb in male group were stronger than in female group. We also noticed that the adjacent and bilateral paired channels represented stronger connection.
